Abstract

Although hypochondriasis is currently classified as a somatoform disorder,
the underlying cognitive processes may be more consistent with an anxiety
disorder. This observation has important implications for treatment and
subsequent revisions of the diagnostic classification of hypochondriasis.

Is hypochondriasis an anxiety disorder?

According to
DSM–IV–TR,1
the central feature of hypochondriasis is the preoccupation with fears of
having a serious medical illness based on misinterpretations of benign (or
minor) bodily sensations. The DSM–IV–TR also emphasises a `disease
conviction' that persists despite appropriate medical evaluation and
reassurance of good health. Preoccupation with medical illness in
hypochondriasis might focus on specific signs or symptoms (e.g. sore throat),
diseases (e.g. cancer) or vaguely defined somatic phenomena (e.g. `my aching
veins'). Typically, the individual attributes unwanted bodily sensations to
the possible disease (e.g. `this headache means I have a brain tumour') and is
highly concerned with their cause and authenticity. Perhaps the most readily
observable sign is the persistent attempt to seek information and reassurance
about the feared symptoms or illness. Individuals with this condition may
repeatedly contact doctors, seek additional tests, scour internet sites and
medical texts, and seek reassurance from significant others about bodily
sensations which have been appropriately evaluated and judged to be benign. As
a result of these emotional, cognitive and behavioural manifestations,
hypochondriasis is often disruptive to social, occupational and family
functioning, and its associated economic costs are
substantial.2

Historically, hypochondriasis has been regarded as resistant to
psychological
treatment.3 This
view may be partially attributable to the absence of a unified conceptual
model of hypochondriasis. Indeed, some have argued that hypochondriasis is
best viewed as a personality
disorder,4 a result
of psychic conflict or as secondary to depression. More recently, however, the
development of a cognitive–behavioural model of hypochondriasis has led
to an efficacious psychological treatment. The cognitive–behavioural
approach is derived largely from the observation that symptoms – at both
a topographical and functional level – overlap remarkably with certain
anxiety disorders: namely, panic disorder and obsessive–compulsive
disorder.5 These
observations are supported by empirical findings which raise the question of
whether hypochondriasis is best considered an anxiety disorder.

Cognitive and behavioural mechanisms shared with anxiety
disorders

Overlaps between hypochondriasis and other disorders might be found on two
levels. The first and least conceptually compelling is superficial similarity.
Like obsessive–compulsive disorder, hypochondriasis involves intrusive,
distressing thoughts and repetitive behaviours. Similarities have been noted
between hypochondriasis and certain presentations of
obsessive–compulsive disorder such as contamination fear, in terms of
preoccupation with health and disease, and the repetitive and pervasive nature
of such
preoccupation.6 The
prominent preoccupation with bodily symptoms in both hypochondriasis and panic
disorder has also invited comparisons between these
conditions.7 Like
those with hypochondriasis, patients with panic disorder are hypervigilant to
benign, arousal-related body sensations and often erroneously attribute them
to organic causes such as heart attacks, strokes and other serious medical
conditions.

The second level of overlap is more interesting. When behaviour is
meaningfully linked to beliefs, a certain degree of convergence may be
expected; consistent links are especially likely when the perception of threat
(and therefore anxiety) is
involved.8 For
example, in both hypochondriasis and obsessive–compulsive disorder,
dysfunctional beliefs (e.g. overestimation of the likelihood and severity of
having an illness, intolerance of uncertainty about the meaning of feared
stimuli) are associated with an increase in subjective anxiety and distress,
and the efforts to check or seek reassurance about the symptoms are associated
with an immediate reduction in
anxiety.8 Put
another way, compulsive rituals in obsessive–compulsive disorder and
reassurance-seeking and checking in hypochondriasis serve as `safety
behaviours' which are designed to restore a sense of wellbeing and a degree of
certainty about the future. Unfortunately, these behaviours paradoxically
maintain the very concerns they are intended to alleviate by: (a) preventing
the natural extinction of anxiety; (b) interfering with the correction of
mistaken beliefs and interpretations of feared stimuli; and (c) increasing
preoccupation with feared
stimuli.8 Thus, the
common psychological process in obsessive–compulsive disorder and
hypochondriasis is the perception that some feared catastrophe will occur at
some future time.

The cognitive and behavioural mechanisms that propel hypochondriasis are
also similar to those that maintain panic disorder, with the exception that
the feared catastrophe is foreseen as occurring somewhat immediately,
resulting in the urge to immediately escape. Both panic disorder and
hypochondriasis involve hypervigilance to bodily sensations and exquisite
sensitivity to even benign (and unexplained)
sensations.9
Moreover, the tendency to misinterpret innocuous bodily symptoms as physically
harmful (i.e. anxiety sensitivity) is associated with both panic disorder and
hypochondriasis.10
The combination of excessive body vigilance and high anxiety sensitivity leads
to the catastrophic misinterpretations of somatic cues (`this symptom means I
have a tumour') which evokes hypochondriacal fear and panic attacks. The
coping strategies, such as body checking and seeking medical
reassurance,11 that
individuals with hypochondriasis and panic disorder use to manage their
anxiety paradoxically maintain or even exacerbate the cognitive mechanisms
that underlie these disorders.

Treating hypochondriasis as `health anxiety'

For most of the 20th century, psychodynamic and psychoanalytic
conceptualisations dominated the treatment of hypochondriasis. In this
context, hypochondriasis was poorly understood and was considered resistant to
psychotherapy. In the past two decades, however, a model of hypochondriasis as
`health anxiety' has been advanced that draws from the cognitive (i.e.
dysfunctional beliefs, body vigilance, anxiety sensitivity, intolerance of
uncertainty) and behavioural (i.e. avoidance, safety-seeking) processes
implicated in the development of other anxiety
disorders.12 This
conceptualisation has been translated into specific treatment techniques that:
(a) help patients recognise and modify faulty beliefs about illness such as
`all bodily sensations are signs of serious illness'; and (b) eliminate
behavioural responses that prevent the self-correction of faulty beliefs.
Although in its early stages, research on the effects of
cognitive–behavioural therapy (CBT) for hypochondriasis has produced
encouraging results. In one study, CBT was found to be superior to no
treatment in reducing health anxiety, the need for reassurance and the
frequency of checking
behaviour.13 A
subsequent study also found that CBT was more effective than stress management
in reducing illness fears and unnecessary medical visits in
hypochondriasis.14
Compared with usual medical care, CBT has been shown to produce more
improvement in health anxiety, hypochondriacal attitudes and beliefs, and
quality of life;15
it has also been found to be more effective than pill placebo and as effective
as the drug
paroxetine.16 In a
recent study, greater improvements in health anxiety and less use of health
service consultations were observed in patients treated with CBT relative to a
control
group.17

Conclusions

Recent DSMs classify hypochondriasis as a somatoform disorder marked by a
collection of signs and symptoms with a focus on the body. Unfortunately, the
DSM's reliance on superficial phenomenological similarities to group
hypochondriasis with the somatoform disorders obscures the important
functional mechanisms hypochondriasis shares with anxiety disorders. It also
ignores the fact that the cardinal feature of hypochondriasis is anxiety about
one's health, and not the presence of abnormal or excessive somatic symptoms.
As a result of this (mis)classification, there has been a noticeable delay in
the development of theoretically grounded paradigms for understanding and
treating hypochondriasis. The cognitive–behavioural view of
hypochondriasis as health anxiety appears to hold substantial promise.
Although this model is based largely on phenomenological and functional
similarities between hypochondriasis, obsessive–compulsive disorder and
panic disorder, it should be noted that individuals with generalised anxiety
disorder often display excessive and persistent worries about their
health,5 and some
types of specific phobias (i.e. illness phobia) also involve irrational fear
and avoidance of particular health contexts that are reminders of illnesses.
In light of these considerations, categorising hypochondriasis in DSM–V
as an anxiety disorder is most consistent with empirical and clinical
observations about the nature and treatment of this disorder.